Light Absorption and Emission Dominated by Trions in the Type-I van der Waals Heterostructures

Abstract By first-principles calculations, we investigate the geometric stability, electronic and optical properties of the type-II PN-WSe2 and type-I PAs-WSe2 van der Waals heterostructures(vdWH). They are p-type semiconductors with indirect band gaps of 1.09 eV and 1.08 eV based on PBE functional respectively. By applying the external gate field, the PAs-WSe2 heterostructure would transform to the type-II band alignment from the type-I. With the increasing of magnitude of the electric field, two heterostructures turn into the n-type semiconductors and eventually into metal. Especially, PN/PAs-WSe2 vdWH are both high refractive index materials at low frequencies and show negative refractive index at high frequencies. Because of the steady absorption in ultraviolet region, the PAs-WSe2 heterostructure is a highly sensitive UV detector material with wide spectrum. The type-II PN-WSe2 heterostructure possesses giant and broadband absorption in the near-infrared and visible regions, and its solar power conversion efficiency of 13.8% is higher than the reported GaTe–InSe (9.1%), MoS2/p-Si (5.23%) and organic solar cells (11.7%). It does project PN-WSe2 heterostructure a potential for application in excitons-based solar cells.

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Dispersion Property and Evolution of Second Harmonic Generation Pattern in Type-I and Type-II van der Waals Heterostructures

ACS Applied Materials & Interfaces ◽

10.1021/acsami.1c07441 ◽

2021 ◽

Author(s):

Chuan He ◽

Ruowei Wu ◽

Mei Qi ◽

Yuanyuan Huang ◽

Yixuan Zhou ◽

...

Keyword(s):

Second Harmonic Generation ◽

Harmonic Generation ◽

Second Harmonic ◽

Van Der Waals ◽

Dispersion Property ◽

Type I ◽

Type Ii ◽

Van Der Waals Heterostructures

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Strain-mediated type-I/type-II transition in MXene/Blue phosphorene van der Waals heterostructures for flexible optical/electronic devices

Journal of Materials Chemistry C ◽

10.1039/c6tc04349f ◽

2017 ◽

Vol 5 (4) ◽

pp. 978-984 ◽

Cited By ~ 82

Author(s):

Zhonglu Guo ◽

Naihua Miao ◽

Jian Zhou ◽

Baisheng Sa ◽

Zhimei Sun

Keyword(s):

2D Materials ◽

Van Der Waals ◽

Electronic Devices ◽

Type I ◽

Type Ii ◽

Two Dimensional ◽

Van Der Waals Heterostructures ◽

Blue Phosphorene

Development of novel van der Waals (vdW) heterostructures from various two-dimensional (2D) materials shows unprecedented possibilities by combining the advantageous properties of their building layers.

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Modulation Electronic Properties of Silicane/SnSe2 Van der Waals Heterostructures Using External Force and Electric Field

Advances in Materials Science and Engineering ◽

10.1155/2021/9986781 ◽

2021 ◽

Vol 2021 ◽

pp. 1-7

Author(s):

Gang Xu ◽

Yelu He

Keyword(s):

Electric Field ◽

Applied Electric Field ◽

High Performance ◽

Van Der Waals ◽

Type I ◽

Normal Strain ◽

Van Der Waals Heterostructures ◽

Electronic Band ◽

Fundamental Research ◽

Metal Phase Transition

In recent years, much interest in the study of Van der Waals heterostructures (vdWhs) has arisen. This has led to a significant amount of fundamental research being produced, from which novel optoelectronic applications have been established. By using first principles, we analyze the electronic structure of silicane/SnSe2 vdWhs in the response to an externally applied electric field and a normal strain. The results show that the silicane/SnSe2 vdWh acts as an indirect semiconductor when it is subjected to an applied electric field between −1 and 0.1 V/Å and becomes a metal in the 0.2 to 1 V/Å range. Significantly, the electronic band alignments of the silicane/SnSe2 vdWhs are modified from a type-II to a type-I when a field of −0.7 V/Å is applied. Furthermore, it is determined that the silicane/SnSe2 vdWhs appears to have a semiconductor-metal phase transition at a strain of −5%. Our results indicate that the silicane/SnSe2 vdWhs have the potential for applications in novel high-performance optoelectronic devices.

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